DNS Ports

[Jonathan de Boyne Pollard]

DH> I am setting up Iptables [...]

<URL:http://homepages.tesco.net./~J.deBoynePollard/FGA/dns-shaped-firewall-holes.html>

DH> I know DNS uses UDP to send and get data.

You need to un-learn this, because it is wrong.  See the 
web page for details.